I currently use both physics.SE and math.SE, and one difference I noticed was the new activity counters and notifications on PSE, which were absent in its math counterpart. Now, in my experience so far, these labels and notifications, albeit not intrusive, make it harder to concentrate while brow...

@SirCumference thomas carlyle called economics "the dismal science" in 19th century... but wrt justification of slavery... lets note physics was a rather "dismal science" pre Galileo. econophysics is a very young new science being born before our eyes. maybe/ hopefully its future form will be far more sophisticated/ evolved than anyone can imagine right now.

what does "non-thermal energies" means? I see it in "I am mainly interested in the investigation of the processes that may be responsible for the energization of particles to their non-thermal energies in astrophysical environments and for the propagation of such particles in the interstellar and intergalactic medium. ...

... These topics are central to our understanding of the origin of Cosmic Rays both in our Galaxy and in extragalactic sources and are crucial in order to interpret the wealth of data from radio to gamma rays that are becoming available in recent years."

Quantum finance is an interdisciplinary research field, applying theories and methods developed by quantum physicists and economists in order to solve problems in finance. It is a branch of econophysics.
== Background on instrument pricing ==
Finance theory is heavily based on financial instrument pricing such as stock option pricing. Many of the problems facing the finance community have no known analytical solution. As a result, numerical methods and computer simulations for solving these problems have proliferated. This research area is known as computational finance. Many computational...

@MartianCactus I'm not sure of the details, but you need to construct a pair of entangled black holes, which are the mouths of the wormhole, using the exotic matter to stop the wormhole from collapsing. Then you need to move the mouths to where you want them. If you want a time difference between the mouths, I think you need to do that movement at relativistic speed, to get some time dilation.

You need a fairly large amount of mass / energy to create black holes. Although in theory BHs can have small mass, we don't know any way to achieve the required energy density apart from getting a few sun's worth of mass to collapse.

Even if we found some way of applying enough pressure to compress an Earth-sized chunk of matter smaller than its Schwarzschild radius, that wouldn't be much use for transportation, since the radius of the mouth of such a wormhole would only be a few centimetres.

I suppose you could charge up your wormhole mouths, so you can drag them around electrostatically. Of course, moving anything that massive will chew up a lot of energy.

Suppose the AdS/CFT formulation also holds for our universe and that spacetime is really a tensor network of entanglements, it seems to dig a hole requires modifying the network topology somehow so that there will be regions where the network is less densely packed with edges

Problem is it is not clear if the thing that is entangled are even quantum states as we knew it, or something more exotic

I had a feeling whatever that makes up spacetime is something more weird than wave functions

and also "very small" otherwise we would have noticed it already in low energy experiments

Might look up one day to see what the tensor network corresponding to some wormhole like geometry in AdS look like

In the many worlds theory in QM, whenever we observe anything that is in a superposition, "reality splits" into different worlds each observed each of the possible outcomes. So my question is when something is in a superposition? I mean, my book gives example with the PETE box (50% chance a ball to be black, 50% to be white) and reality splits and there are 2 identical observers, each observed each possible outcome.

@PM2Ring So if you move the mouths to where you want them then you cant travel between galaxies instantly? As popular belief says. Then that means you can only travel to a place you already have been..

@MartianCactus Once the mouths are where you want them, yes you can travel almost instantly through the wormhole. But it will take you 2.5 million years (relative to Earth) to transport a mouth to Andromeda, if you can do that near light speed.

But I defer to Slereah on this topic, since they know far more about gluing spacetimes together than I ever will.

@MartianCactus No. As Secret said, there's the possibility that at the ultra-small scale spacetime already has an existing network of naturally-occuring wormholes, we just have to figure out a way to expand the mouths to a useful size, and then use exotic matter to keep our chosen wormhole open. But I have no idea how you could select where the other end of such a wormhole is. And that expansion operation probably needs a huge chunk of energy.

But to create a wormhole when previously there isn't any, seemed to be more challenging

The mechanism of a topological change interested me more, but I guess it will be very energy intensive to do that

though practically speaking, if there are already a lot of naturally occurring wormhole networks, then perhaps this existing set will always have the correct pair to do the job

thus all that boils down is the huge energy requirement, as well assumptions that gravity still behave in a predictable way at that scale, which we don't know since we don't have a quantum gravity theory yet

@JMac They're mashing together various numbers from physics & looking for matches. When they find one, they see it as evidence for some hitherto unexpected connection. Generally, the match doesn't need to be very close. Here's an example from XKCD. forums.xkcd.com/viewtopic.php?f=18&t=108599

I'm tempted to close as unclear. It is clear to me what they're doing, but it sure ain't physics.

> Despite all the mythology to the contrary, I actually just came up with the 'Jenny,' and the telephone number and the music and all that just sitting in my backyard. There was no Jenny. I don't know where the number came from, I was just trying to write a 4-chord Rock song and it just kind of came out.

Just my attempt to make something more intense than "not even wrong" but is heavily restrained by the language used

The same phenomenon happens whenever one tries to talk about any of the unknown categories

Put it another way, what I want to say up there is numerology is generally worse than "not even wrong" because given the huge number of mathematical coincidence, the chance that a coincidence is meaningful is virtually zero, thus numerology does even worse than astrology

@EmilioPisanty Well, I just don't bother to rank between them, though I think the concave earth is the most absurd of them all. You can still fit some real life evidence to flat earth if you tried hard enough, but concave earth throws everything out of the window

Also Semi, you brought out a good point here:

> people's personalities and actions having an unknown influence on the universe

Pseudoscience that falls into this category tend to be much less internally consistent due to egotism, banum effect, dunning Krueger phenomena and other principles

Interestingly, Having knowledge of both quantum woo and proper understanding of quantum mechanics makes me realise one important thing: Magic as depicted in folklore and in fictional works are actually very powerful because they are basically superluminal signalling

@MartianCactus Kind of, but they're quantum-stabilized micro black holes, so they don't radiate, and they're too small to swallow anything. But I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. ;)

@EmilioPisanty I'd be more than mildly ticked by that. It's distorting what you're saying!

@KyleKanos I have no idea. The TeX-to-internal-system conversion in phys rev is meant to be super streamlined and automatized, so who knows what happened there. Also it was ages ago, so it's mostly lost to time. But it still annoys me.

@Secret to be honest I'm more annoyed by the consistent mis-alignment of equals signs in equation arrays

@MartianCactus I repeat, I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. But anyway... We're talking about really tiny BHs, down at the Planck scale, forming the structure of spacetime itself. So in this picture, spacetime is an almost perfectly uniform field of these micro wormholes / black holes. They don't pull anything around, because any particle is being pulled equally in all directions.

But I guess you can "blame" them for stuff like inertia, and the actual value of the speed of light.

I don't claim this theory is true, and I may have messed up the details, it's been years since I read about this stuff. I'm just saying it's a possibility that's been kicked around.

@ACuriousMind Agreed. OTOH, I remember a few decades ago it wasn't considered totally crazy to speculate that fundamental particles are quantum-stabilized micro black holes. So using them as the components of quantized spacetime isn't much more crazy. ;)

@MartianCactus I repeat, I'm no expert in possible quantum gravity theories, so I May Be Totally Wrong. But anyway... We're talking about really tiny BHs, down at the Planck scale, forming the structure of spacetime itself. So in this picture, spacetime is an almost perfectly uniform field of these micro wormholes / black holes. They don't pull anything around, because any particle is being pulled equally in all directions.

This non mainstream thing is quite intuitive though, because any black holes has entropy proportional to its horizon area, which under that formalism, can be explained as the tensor network of micro black holes

It also explain nicely why black holes will merge and expand their horizon area, because what is happening is that an ensemble of micro black holes interact and then they became entangled, adding to the bulk and creating an anisotropy which is felt as gravity

but again, I don't think even quantum fields make sense in quantum gravity, thus this intuitive picture is likely to be way off

In physics, there is a speculative notion that if there were a black hole with the same mass, charge and angular momentum as an electron, it would share other properties of the electron. Most notably, Brandon Carter showed in 1968 that the magnetic moment of such an object would match that of an electron. This is interesting because calculations ignoring special relativity and treating the electron as a small rotating sphere of charge give a magnetic moment that is off by roughly a factor of 2, the so-called gyromagnetic ratio.
However, Carter's calculations also show that a would-be black hole...